Recently, a home/residential base station called a “Femto base station (Femto-BS)” is proposed as a solution to the problem regarding a limited power reception level of a user equipment (UE) such as a mobile phone especially in remote areas and in residences. The Femto-BS generates a service area called as a Femto cell providing in-home mobility with maximum user data rates without loading a macro cell provided by macro base stations (macro-BSs).
A radius of the Femto cell is approximately 10 meters and the Femto-BS provides the indoor coverage of the macro-BSs within a residence. It also increases the capacity of the data transmission to and from the user equipment, when the entire residence is in the macro-BS's coverage.
The Femto-BS deployed at home usually has an idle period, for example, at night where the user of the Femto-BS is sleeping. If the Femto-BS enters an energy-saving mode (ES mode) from a normal operation mode to turn off a Downlink (DL) transmission from the Femto-BS to the UE connecting to the Femto cell for such a long period, it may save electricity at home. After the Femto-BS enters the ES mode and turns off the DL transmission, the end-user must turn it on manually using a mechanical switch of the Femto-BS or a near field communication (NFC), because a UE generally requires the DL common channels (DLCCH) from the base station before it initiates a call or data transmission through that base station. In addition, the UE may request to update software and its configuration or to download contents as a background operation while the UE itself is not used by the user overnight.